Enhancement of the Sterile Insect Technique (SIT) through Genetic Transformation Using Nuclear Techniques


Develop efficient genetic transformation systems for major insect pests, and improve the efficiency and cost-effectiveness of the sterile insect technique.


For several insect species, SIT has proven to be a powerful method for population control. This includes the New World screwworm fly, the Mediterranean fruit fly, the melon fly, the Queensland fruit fly and the tsetse fly. This CRP was directed to developing transgenic technology so that it may be applied to improve the SIT for these and other species of insect pests.

To develop such technology, research on both vector development and transformation genes was undertaken.

Although many transposable elements have been studied in a variety of organisms, only few have been used as gene vectors, and it has been suggested that the identification of a universal vector is unlikely. Research on other elements such as mariner, Tc-1 like and viral based systems is therefore absolutely necessary. In addition to the characterization of potential transformation vectors, research was aimed at the identification of useful marker genes.

For the development of advanced genetic sexing strains it is necessary to be able to manipulate sex at the molecular level. Research was therefore undertaken to identify and eventually clone the relevant genes. Also, for the discrimination of released and wild flies work was carried out on molecular tags inserted into strains, thereby complementing or even eliminating the not completely satisfactory procedure based on fluorescent dyes.

In addition to the genes/traits of interest, appropriate promoters have to be isolated. Therefore, genes with sex or tissue-specific expression were isolated and characterized. Of particular interest were also the promoters of genes that can be activated by environmental stimuli, e.g. heat.


Ten Agreement Holders from Greece, Italy (3), New Zealand, UK, USA (4).